With the U.S. wanting to send astronauts on long trips to Mars, it's important to make sure disease prevention tactics are in place

While NASA's disease prevention methods have worked pretty well for shorter trips, like those to the International Space Station (ISS), American space travel is looking to send astronauts to Mars in the future and stronger germ-fighting techniques may be in order.

Dr. Leonard Mermel, a Rhode Island Hospital infectious disease expert from Brown University, has written a new paper of suggestions that could keep spacecrafts germ-free during longer expeditions -- such as to Mars.

After reading hundreds of papers about infectious diseases and citing 91 of them in his paper, Mermel came to a few conclusions that could prove problematic for long-term missions. These problems include the fact that limited power means no complex air filtration (which also means no use of disinfectants or hand hygiene products because they can emit hazardous vapors; microgravity can weaken the immune system in some ways while also increasing resistance to some microorganisms, and without gravity, germs from a sneeze do not simply hit the ground; they linger in the air.

What does Mermel suggest? Beefing up NASA's current disease prevention methods. This means vaccinating astronauts for several diseases and screening for many others, which NASA already does, but extend the vaccinations to include germs like Meningoccocus and Pneumoccocus. Screenings can be done pre-flight to include many strains, such as Staphyloccocus.

Aside from that, Mermel also suggested that astronauts receive formal infection control education and a new, low-energy diagnostic testing kit.

NASA could also consider whether to irradiate more food for longer trips, since food could be a source for germs. Irradiating the food means making it completely sterile, but it could be harmful for astronauts to eat sterile food for two whole years.

Further, Mermel believes future spacecraft makers could include HEPA air filtration as well as waterless hand hygiene dispensers.

"I've been involved for two decades with trying to prevent infections in the intensive care unit and general hospital settings and I've been involved with national and international guidelines, but there are a lot of constraints in space I had never thought of before," said Mermel.

U.S. President Barack Obama challenged NASA to put a man on an asteroid by 2025 and explore Mars in 2030. With such endeavors in mind, securing spacecrafts from as many germs as possible might be a good idea.